attribute vec4 a_position;
attribute vec4 a_color;
attribute vec2 a_texCoord0;
uniform mat4 u_projTrans;
varying vec4 v_color;
varying vec2 v_texCoords;
void main() {
    v_color = vec4(1, 1, 1, 1);
    v_texCoords = a_texCoord0;
    gl_Position = u_projTrans * a_position;
}